Synthesis and Supramolecular Architectures of Dinuclear Metallacyclic Silver(I) and Zigzag‐Chain Copper(II) Complexes Bearing 2,6‐Pyridinediylbis(3‐pyridinyl)methanone

Abstract

The reaction of 2,6‐pyridinediylbis(3‐pyridinyl)methanone (abbreviated as L) with various silver(I) salts yielded a series of complexes, namely, [Ag2(L)2](ClO4)2 (1), {[Ag2(L)2](ClO4)2}∞ (2), {[Ag2(L)2](NO3)2}∞ (3), {[Ag2(L)2](C2F5CO2)2}∞ (4), {[Ag2(L)2](C3F7CO2)2}∞ (5), and {[Ag2(L)2](O2CC3F6CO2)·2H2O}∞ (6), which exhibit a common dinuclear metallacyclic [Ag2(L)2]2+ skeleton that involves linear‐dicoordinate AgI and μ2‐N,N‐bridging L. Complex 2 is a polymorph of 1 obtained by the solvent‐medium tuning effect, and it has an {[Ag2(L)2]2+}∞ infinite‐chain structure. In complexes 3–6, the argentophilic interaction plays an important role in connecting the [Ag2(L)2]2+ units to form a similar {[Ag2(L)2]2+}∞ chain structure to that in 2, although the counteranions are markedly different. The copper(II) complex {[Cu2(CH3CO2)4(L)]·2H2O}∞ (7) exhibits a zigzag‐chain structure composed of an alternating arrangement of L and the Cu2(CH3CO2)4 paddlewheel cluster. In the supramolecular architectures of 1–7, the counteranions engage in multiple noncovalent interactions, and the presence of unusual types such as O/F(anion)···π, O/F(anion)···C=O, and C=O···π are noted and discussed.

Argentophilic Interactions

“…This pattern of interactions varies very little with other anions (nitrate or C 2 F 5 CO 2 ). [155] In the nitrite, two silver atoms are located in a 28-membered ring. Instead of a direct transannular argentophilic interaction, an additional silver atom (with two nitrite ligands) becomes the central element of an Ag-Ag-Ag bridge with distances of 3.014(1) and 3.043(1) (type 35 d).…”

Crystal structure of poly[(μ2-6-methyl 6-nicotinoylpicolinate- κ4O,O’,N:N’)-(tetrafluoroborato-κ1F)silver(I)], C13H10AgBF4N2O3

“…Herein, we report one new silver(I) complex derived from 6-nicotinoylpicolinate, an asymmetric ketone. In the title complex, the Ag(I) exhibits afive-coordination geometry with each silver(I) center surrounded by two pyridylNa tomsf rom two different 6-nicotinoylpicolinate ligands with Ag-N distances of 2.184(5) Åand 2.248(4) Å [6],one F(BF 4 -)weakly bonded at 2.606(3) Å [7] and two carbonyl oxygen atomsat2.617(5) Åand 2.630(2) Å [8]. The C=O bond length is 1.207(6) Å, the angle C(sp2)-C-C(sp2) equals 119.7(5)°.…”

Effect of anion on Ag(i)meso-helical chains formed with 4,4′-dipyridyl ketone: solventversusanion bridging and anion effects on the strength of ligand binding

“…They should be prepared in small amounts and handled with care. This journal is © The Royal Society of Chemistry 2014 Table 3 Crystal and structure refinement data for complexes 11.020 (11) 11.0709 710.950 (7) b/Å 11.2371 (8) 9.8846 419.1191 (10) 18.8411 (11) 22.9536 1510.6328 518.3216 1718.5174 (12) 11.1081 (7) c/Å…”

“…The adjacent meso-helical chains were formed into antiparallel pairs through two complementary interactions. One of which was weak π-π-interactions involving all of the pyridine rings of the adjacent chain [centroid-to-centroid distance 3.763(2) Å, inter-planar dihedral angle 3.62 (8) Slow evaporation of the solvents from a 1 : 2 molar reaction between AgClO 4 and L resulted in X-ray quality colourless crystals of 3. Again, the microanalysis was consistent with a 1 : 1 formulation.…”

“…3 Introduction of a bend in these ligands presents a new variable to the study of the coordinating aspects of these linear linkers. The bend provides an opportunity to study lower dimensional structures such as helical, 4 meso-helical, 5,6 zigzag [7][8][9] chains and other structures of current interest. 10 One simple bent ligand is 4,4′-dipyridyl ketone (L) (Fig.…”